One of the higher profile apps in the Windows Phone Store is causing some issues with some people in the US. The app is Adobe Reader and this weekend, reports started coming in that Windows Phone users who are prompted to install a new update get an older version of the PDF reader software than the one they already had installed.

Specifically, WPCenter.com reports that the update actually downgrades Adobe Reader back down to version 9.0. The last version for Windows Phone devices is 10.1, which was launched three weeks ago. It's currently unknown why this situation is happening but at the moment it appears to be affecting only US Windows Phone owners.

Microsoft recently has been making a big deal of the fact that they have been making improvements to the Windows Phone Store (the new name for the previously branded Windows Phone Marketplace). However, it's clear that there are still some bugs and issues that need to be addressed.

With the launch of Windows Phone 8 just a few weeks away, Microsoft might have to double check their work to make sure everything is set correctly in order for the expected new rush of Windows Phone users in the coming months.